I mean they also had Trump on during 2016. Why is anyone even remotely surprised by this? They are a show. They work for ratings. Having someone running for President on there kinda makes sense number wise.
Less surprise and more disappointed. They are doing the same thing the news stations did during Trump's first presidential run: giving them free advertising.
If they don't court their fan's favor, they will decline (again) in popularity. One-off stunts for ratings that are unpopular have the potential to hurt them in the long run.
As a conservative I feel like right wing social media spins have been more cringe and ridiculous than usual. First the Taylor Swift stuff, now this...ugh.